As technology development and demand for mobile devices have increased, there has been a rapid increase in demand for rechargeable batteries as energy sources. Among such the rechargeable batteries, a lithium rechargeable battery with high energy density and operation potential, and a long cycle life, has been commercialized and widely used.
Since the lithium rechargeable battery contains various combustible materials, there is a danger of heat generation and explosion due to overheating, overcurrent, physical external impact, etc. Therefore, it has a serious disadvantage in safety. Thus, the lithium rechargeable battery is connected to a battery cell corresponding to a safety element such as a positive temperature coefficient (PTC) element, a protection circuit module (PCM), or the like that is capable of effectively controlling an abnormal state such as overcharging, overcurrent, etc.
Since the rechargeable battery is preferably manufactured to have a small size and light weight, a prismatic battery or a pouch-type battery having light weight compared to capacity thereof is mainly used as a battery cell of a rechargeable battery. Particularly, the pouch-type battery using an aluminum laminate sheet or the like as an exterior member has recently attracted a lot of attention due to its advantages such as light weight and low manufacturing cost.
In the pouch-type battery cell, a PCM is fixedly connected to an electrode of the battery cell in a state in which the battery cell is installed at a case thereof, a label is attached to an outer surface of the case, and thus the pouch-type battery cell is completed. For example, the case may have an assembly structure with an upper cover and a lower cover for covering an outer surface of the battery cell, or may have a separate fixing member for fixing a corner portion of the battery cell.
In addition, in order to mount the battery cell on an application product, it is generally necessary to accommodate the battery cell in a frame to protect it from external vibration or impact.
However, according to a trend of a small size and high performance of the mobile device, since a small size and high capacity of the battery pack is required, a battery pack capable of providing larger capacity at the same size is increasingly required. In addition, there is a high need for a manufacturing method of a battery pack that may reduce a manufacturing cost by simplifying a manufacturing process and improve stability against external impact.